1. Field of the Invention
The present invention relates to covering materials, such as for example the laminar covering materials that can be used in the building and furnishing sectors, in particular for the construction of floorings.
2. Description of the Related Art
The wide variety of covering materials of this type currently available fall into three basic categories.
One category that perhaps dates furthest back in time corresponds to the covering material commonly referred to as linoleum. The corresponding production technique basically envisages adding to linseed oil filling materials, such as wood flour and cork flour, mineral fillers, pigments and other additives so as to obtain a so-called linoleum paste. This paste then undergoes rolling in order to form sheets, which in turn undergo a so-called “curing” step, which lasts some dozens of days and is basically aimed at achieving a consolidation of the sheet of linoleum sufficient to enable its further handling and treatment (for example, so as to enable winding thereof into rolls for subsequent laying).
Notwithstanding its long existence over time, this category occupies only quite a modest share of the market both on account of the disadvantages linked to the intrinsic lengthiness of the process of curing and because, in the steps subsequent to laying of the flooring, linoleum tends to release into the environment an intense and characteristic odor linked to the presence of linseed oil.
A very substantial slice of the market of coatings and floorings is represented by synthetic plastic materials. One of the most widely used materials for making these coatings, which is able to present a contained cost, is represented by polyvinyl chloride (PVC). Irrespective of any other consideration, these floorings, and in particular PVC-based ones, tend to be viewed with less favor on account of the substances (for example, compounds of chlorine and plasticizing agents) that can be released by the coating, also on account of their disagreeable smell.
In the course of the last few years, rubber-based floorings have met with particular favor. These floorings are able to combine excellent characteristics of use (for example, as regards resistance to mechanical stresses, to aggressive chemical agents, and to burns) and as regards the possibility of obtaining coatings and floorings that are particularly pleasant from the aesthetic standpoint (for example, with general marbled effects or effects of dispersion of granules of different colors). Examples of this prior art are provided by EP-A-0 968 804 and EP-A-1 020 282.
Over the years there has been no lack of attempts to merge the characteristic elements of the various techniques of production considered previously. For example, in EP-A-0 385 053 there are described coatings of linoleum with the addition of rubber, the main purpose being to enable exploitation of the process of vulcanizing of the rubber in order to make available a coating of linoleum that can be handled and transferred to the site of laying in far shorter times than those characteristically required for curing linoleum floorings of a traditional type.
Even though the solutions described in the known art, have proven to be satisfactory and advantageous to use, there still exists the possibility of achieving further improvements above all as regards the possibility of further improving the mechanical characteristics of the covering material, the resistance to external stresses (particularly as regards the stresses due to treading), and the possibility of widening even more the choice of the chromatic ranges for making the coating.